*1 When the option front protection cover is installed on the one of transmitter or receiver, the Operating distance is shorten by 1.64' 0.5 m. When the front covers are installed on both of the transmitter and receiver, the Operating distance is shorten by 3.28' 1.0 m.*2 If the interruption is present in the detection zone for less than 80 ms, the response time (OFF to ON) will be 80 ms or more to ensure that the OSSD maintains the OFF state for more than 80 ms.*3 “All blocked” means the situation where the GL-R operates in optical synchronization system and thetransmitter and receiver is not synchronized (top and bottom beam axes are both blocked). In this situation,the response time is longer because the GL-R synchronizes the transmitter and receiver fi rst and thendetermines the clear or blocked.*4 When the GL-R is used under surrounding air temperatures between 50 to 55°C 122°F to 131°F, the Maximum load current should not exceed 350 mA.